More people than ever are using mobile stations, such as cell phones and personal digital assistants, to connect to wireless wide area networks (WWANs), each of which (or a plurality taken together) may also be referred to as a radio access network (RAN) and by other names. Service providers typically operate RANs to provide both voice and data services using a wireless communication format (i.e., protocol) such as CDMA (e.g., 1 xRTT, IS-856), EV-DO, iDEN, TDMA, AMPS, GSM, GPRS, UMTS, EDGE, WiMAX (e.g., IEEE 802.16), LTE, microwave, satellite, MMDS, Wi-Fi (e.g., IEEE 802.11), Bluetooth, infrared, and/or other protocols now known or later developed.
Mobile stations typically include a processor, a transceiver circuit, and an operating system that together provides basic functionality, such as supporting the voice and data services noted above. The processor provides execution cycles for executing machine language program code associated with the operating system, and/or one or more various applications running on the operating system. The transceiver circuit in the mobile station facilitates the voice and data services by providing a wireless interface to a wireless service provider network. A battery contained within the mobile station provides power to the processor and the transceiver circuit. The battery can be charged at home, for example, and provides enough power to operate the processor and transceiver circuit for a limited amount of time. Typical battery life for mobile stations can range from, for example, 3-8 hours.
Various applications may also be available on mobile stations that provide enhanced functionality beyond the simple voice and data services provided by the operating system. These various applications may include mapping programs, e-mail clients, calendars, web browsers, video-streaming clients, games, social-networking tools, weather programs, etc. Each of these various applications may be allocated mobile station resources, perhaps by the operating system, for executing their corresponding functions on the mobile station.
For example, mobile station resources may include a number of execution cycles on the processor, a radio frequency (RF) transmit power of the transceiver circuit for transmitting voice and/or data to the RAN, or a number of times per unit of time that the applications are allowed to contact the RAN with new and/or updated data requests (e.g., a data-synchronization frequency), among other parameters.
The number of execution cycles allocated to an application may increase for a more complex application, and therefore consume more battery power. Because mobile processors are designed for low-power consumption, parts of the processor will normally be powered down when not in use, so that battery power can be preserved. When a particular application requires additional execution cycles, it causes a commensurate increase in battery-power consumption. Applications such as games that require continuous updates to the screen, and processing of user input, tend to consume more execution cycles, and thus battery power, than less demanding applications such as weather programs.
The RF-transmit power allocated to an application (or perhaps to all applications), may increase depending on the number of errors tolerated in wireless communications (a measure of which is called the “frame-error rate”), and may also increase as the mobile station moves farther away from the nearest access point in the RAN and an application requires data communications. The battery power consumed by the transceiver circuit increases correspondingly with the higher RF-transmit power required. Bandwidth-intensive applications such as video-streaming that demand a lower frame-error rate, and thus an increased RF-transmit power, will cause an increase in battery-power consumption compared to less bandwidth-intensive applications that can tolerate a higher frame-error rate, such as e-mail.
The data-synchronization frequency allocated to an application may vary depending on the characteristics of an application. For example, an e-mail client may be configured to have a higher data-synchronization frequency than a weather application, as e-mail inboxes tend to change more often than the weather, and users typically expect near-real-time access to their e-mail. Because more frequent transmissions by the transceiver circuit results in an increase in battery-power consumption, applications such as e-mail that are allocated higher data-synchronization frequencies will consume more battery power.